Thread: The Importance of Using the Right Data

Greetings All,
The recent thread on the best data for ADI powder got me thinking. Data has changed over time for various reasons so I thought I would share some comparisons to illustrate why current and relevant data only should be used.
I selected the .264 Win Mag as it has a reputation for being a cantankerous cartridge to load for and shows how much things have changed. The .264 Win Mag came out in 1959 and was the new fire breathing Magnum of the time. The slowest powder commonly available at the time was WW2 surplus 4831 offered by Hodgdon at bargain prices. I looked at the current version AR2213SC or H4831SC plus AR2217 or H1000.

For the 129 grain projectile Nick Harvey in his sixth edition (about 2003) listed max loads of 68 grains of AR2213SC and 71 grains of AR2217. The 68 AR2213SC grain load is clearly an error as he lists 3 grains less for the 120 grain projectile. I suspect it has not been corrected from his 1980 manual.
For the 129 grain Hornady soft point the current Hodgdon on line data lists max loads of 62 grains of H4831SC and 64 grains of H1000. Hodgdon also lists, for the 130 grain AB max loads of 59.2 grains of H4831 and 60.4 grains of H1000. These loads are pressure tested in PSI using the modern electronic systems so this is modern data.
For the 130 grain Barnes TSX flat base Barnes does not list H4831 but does list a max load of 62.1 grains of H1000. Barnes does not list either powder for their 127 grain LRX BT but their loads for other powders and this projectile are lower than the 130 grain TSX FB so perhaps a slower powder is needed.

So there we have it, a variation of up to 10 grains in max loads of two powders in published data over less than 20 years. Part is due to better pressure testing methods and likely a larger part to harder construction of the latest whizo projectiles. I think the 3 grain difference between max loads as tested by Hodgdon for the Hornady and the Nosler projectiles tells us something. These loads were likely developed at the same time. Which of these loads would you care to put your face behind and touch off? I have made my decision.
Regards Grandpamac.